Siemens SINAMICS G110D Operating Instructions Manual page 135

Figure 6-22
AS-i is a low speed (166 kbps) two-wire bus and the physical signalling method is
Manchester coded current pulses superimposed on the 28 V power supply. Since the power
supply is used for communications, it must be decoupled with inductors in order for the
receiver to be able to decode the transmitted messages. The basic data exchanged is four
bits in each direction each time a slave is polled. A second cable is used for an auxiliary 24 V
supply which provides power for the electronics inside the Inverter. No communications
takes place of this second cable.
In the diagram below an example is given of how the Manchester coded current pulses are
used for communicating data.
SINAMICS G110D
Operating Instructions, 2009-05-15, A5E02385577A AB
AS-i network structure
6.11 Operation in fieldbus systems
Functions
135